Antiskid device



Oct. 9, 1951 c, w DART 2,570,922

ANTISKID DEVICE Filed Nov. 17, 1948 i II J5 I H -Xk H 4Q INVENTOR H 44 CHARLE S DART Patented Oct. 9, 1 951 UNITED STATES PATENT OFFICE) Application November 17, 1948, Serial No. 60,515

6 Claims. 1,

This invention relates to anti-skiddevices, and

more particularly to tire. chains intended to be used on farm tractors. Farm tractor tires are comparatively thin and-are operated under low pressure, and are provided with large cleats molded in the tread. Despite the treadcleats, chains are often required, and the cleats; low pressure and thinness of the tire all limit the types ofchain which may be used successfully.

One-type of chain which has been successful is that in which a series of short chains are connected to the. side chainsand to center links to producea tread in the form of a series of Xs. The links of the short chains are'veryrlarge in comparison to the stock of which they are made, and: are bent or twisted to present a large traction area no matter how they are presented to the ground.

These large bent or twisted links are subject totwistingunder traction,- which shortens'the chain of which they form part. Because of the thinness of the tire;- such shortening and attendant tightening of the chain asa-whole endangers the tire bydistorting it. Also, the presence'of the cleats on the tread often hinders proper creeping of the chain around the tire, and'it has been observed that the center links sometimes turn over, end for end, with consequent binding of the chain to the tire;

It is with a "construction of tire chain for farm tractors which will exhibit lesstendcn'cy totwist, tangle or bind in use thatthis invention has to do.

It is a primary object'of the present invention to provide a farm tractor chain in which the center links are prevented from turning over.

It is a further. object of the present invention to provide a farm tractor'tire chain in which the tread chains are held against twisting or tangling.

It is a further object of the present invention to provide a farm tractor tirevchain which will creep'around the tire as required. and wiu not permitv spinning of the tire within the "chain;

Referring now to thedrawings:

Figure 1 is a view of a .tire with a chain of the type contemplated in place thereon;

Figure 2 is a detailed view of one of the links of the chain of Figure 1;

Figure 3 is a developed view of the chain of Figure 1, as it appears when laid on the ground with the side engaging the tire uppermost; and,

Figure 4 is a fragmentary view of part of the chain in contact with the tire.

The form of the invention shown comprises a pair of'side chains It], with their ends joined" in the usual manner, to which'are attached the tread assemblies. For this purpose, connectin links H are secured to the side chains at intervals. For the purpose of permitting renewal of the tread chains, each of these links has been shown as comprising a length of stock with an eye formed in each end for retaining the links towhich itis connected.-

Linkedwith each connecting link is a plain link l2, to which in turn is linked a chain of two bent'links l3 and I l. These links l3 and I4, together with the center links form the working part of the'tread. They are characterized by being of large size, in comparison to the size of the stock'of which they are made. Furthermore, their shape is such that there is always a considerable protrusion from the tread, regardlessof the position they take. The shape may be described as being that of a plain link bent about a-line oblique of the long axis of the link. It is 'this oblique bend which causes the links I3 to take the-position shown in Figure 3, the position being one in which the tension is applied from adjacent links along the greatest diameter otiltheslinks l3;

Link-ld of each chainis connected to a center link l5. This center link may be in a number of forms, but-the shown form is illustrative of the principle involved. Link l5 comprises a rectangular frame it, preferably welded, having a pair 'of cross members ll secured to one side thereof,

also=prefrably by welding. The two-ctossmerhbers l'lthusdefine, with the frame I5; three openings: l 8; l S and- 20;

The -=bent links 14- are secured to the centerlink with -their concave sides against the frame [5; and'theircurVed: ends extending around the cross 'bars l 1. Thus each link I4 has a'side'strand Zl passing through the opening IB-QnZBdefined byacross bar I! and the end of the-frame I6, and another-side strand 22 passing through the opening lil defined'by the two cross bars ll'and th'e sidesoftheframe Hi. It will be noted "that the ends 'of each-link I4 passes around the cross bar- I! 'on'the side thereofaway from the frame;

center link to turn over, end for end, when the tractor is operated under heavy draw bar resistance in wet or soft ground.

In addition to this, the engagement of links 14 with the center link is in such a manner that the links 14 cannot rotate about a line transverse the tread. In Figure 3, the straight arrow represents the movement of the tractor axle. 'Movement in that direction tends to rotate links l3 in the direction indicated by the curved arrows in the same figure. They are prevented from so rotating by the engagement of their strands with the strands of links M. Of course, reverse movement of the tractor would tend to rotate links I3, and the restraint of links M is not-efiective until links [3 have rotated almost halfa turn, but, as tractors are not backed under load for any great distance, this is not a serious problem.

In fact, it is possible to construct a chain with alternate links i3 engaging links M in a manner to prevent rotation in the opposite direction. Such a chain would be almost as effective in both directions as existing types are in one direction, as existing types do not prevent rotation of the links corresponding to links M except in one direction.

It was pointed out that the ends of links I4 project from the general surface of the center link to a considerable degree. It has been found that particularly with new and unworn cleats, there is a tendency for the center link to catch on a cleat, and, as the chain creeps, to have its rear end lifted higher and higher until finally the link turns over, binding the chain to the tire. With the present construction this does not happen, regardless of the tightness, or within reason, looseness of the side chains. The rounded ends of the links [4 engaging the tread are in themselves capable of preventing such catching of the center link, but also, the fact that they are loose, and able to move slightly as the tire deflects seems to work them up over the cleats and around the tread without hindrance. This does not mean that the tire will spin within the chain, however, as the usual tension on the side chains will prevent this.

The above description is illustrative of one form of the present invention, and it is to be clearly understood that many variations are possible within ordinary mechanical skill, and accordingly, the scope of this invention is to be determined from the appended claims.

I claim:

1. In a tread assembly for anti-skid devices of the type including a center link and a plurality of tread chains extending therefrom, a center link having a pair of openings, and a chain link having a substantially oval configuration linked thereto by passage of one side strandthrough one opening, and its other side strand through the other opening.

2. In a tread assembly for anti-skid devices of the type including a center link and a plurality of tread chains extending therefrom, a center link having a pair of openings, and a chain link having a curved end and side strands curved out of the plane of said curved end, one of said curved side strands passing through one opening, and

the other side strand passing through the other" opening in the center link, the curved end of the chain link thus lying on the opposite face of the center link from the curved side strands.

3. In a tread assembly for anti-skid devices of the type including a center link and a plurality of tread chains extending therefrom, a center link in the form of a continuous loop defining an opening and having a member extending across the opening of the loop and intersecting the loop, a chain link having side strands and a curved end linked with the center link by passage of the side strands through the opening of the loop on opposite sides of the cross member. 7

4. In a tread assembly for anti-skid devices of the type including a center link and a plurality of tread chains extending therefrom, a center link in the form of a continuous loop defining an opening and having a member extending across the opening of the loop and intersecting the loop, a chain link having a curved end and side strands curved out of the plane of the end, said side strands passing through the opening of the loop on opposite sides of the cross member with their concave surfaces engaging the loop and the curved end engaging the cross member whereby the chain link is held against turning.

5. In a tread assembly for anti-skid devices of the type including a center link and a plurality of tread chains extending therefrom, a center link in the'form of a continuous loop defining an opening and having members extending across the opening of the loop and intersecting the loop, chain links linked to the center link at the intersections of the loop and the cross members, each of said links having curved side strands and curved ends, said side strands of each of said links passing through the opening of the loop on opposite sides of a cross member, with a curved end of each link engaging the cross member and projecting from the general level of the center link.

6. In a tread assembly for anti-skid devices of the type including a center link and a plurality of tread chains extending therefrom, a center link in the form of a continuous loop with cross members extending across the opening of the loop and projecting from one face of the loop, chain links linked to the center link at the intersections of the loop and the cross members, each link having curved ends and curved side strands, the side strands of each link lying with their concave sides against the loop and their curved ends passing around a cross member on the side thereof away from the loop to thereby project from the general surface of the center link.

CHARLES W. DART.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,596,299 Olson Aug. 17, 1926 1,739,522 Reyburn Dec. 17, 1929 1,788,486 Hall et al Jan. 13, 1931 2,235,408 Reyburn Mar. 18, 1941 

